Exposing SAP ECC over internet security concerns

Dear All,

We are on SAP ECC 6.0 EHP7 (NW 7.4). We have developed some of the ODATA services in ECC which we need to provide to external mobile application. For this, we need to expose ECC on internet. We have SAP web dispatcher 7.4 available in DMZ zone. Please suggest

1. Routing access from internet(mobile app) via web dispatcher to ECC

2. Allow only Odata services via webdispatcher url filter

Is this safe way or there is any other safer mechanism.

Thank you